Modular Foldable Surfaces: a Novel Approach Based on Spatial Mechanisms and Thin Shells

This paper investigates a set of novel techniques that lead to modular, deployable surface arrays which could be either flat or curved in their deployed shape. The two components of the proposed concepts are thin shells with smooth folds and spatial mechanisms with rolling hinges. Kinematics of the mechanism and motion of the shell has been shown to be fully compatible with each other during folding and unfolding. This basic module is then articulated to create multiple modular tessellations, which form a series of foldable surfaces. We further demonstrate that curvature could be introduced to the initially flat shells using bonded piezoceramic actuators. The techniques and concepts proposed in this paper could be valuable for the design of future deployable space-based telescope and other reflective arrays which require high shape precision with low storage area and volume.